Fail pending server JS interop calls when circuits disconnect

[imsouvik]

Fail pending server JS interop calls when circuits disconnect

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Summary of the changes (Less than 80 chars)
Fail pending server JS interop calls when circuits disconnect

Description

Server-side JS interop calls are tracked in JSRuntime until EndInvokeJS receives the client result. If SignalR closes the connection before the result reaches EndInvokeJSFromDotNet, such as when the incoming JS interop result exceeds the receive message size limit, the pending call is never completed and only observes caller cancellation or timeout.

This adds a protected JSRuntime helper for derived runtimes to fail all pending async JS calls, and has RemoteJSRuntime use it when the circuit disconnects or transfers to another connection. It also rejects new JS interop calls while the circuit client is disconnected and attempting to reconnect.

Fixes #67479.

Testing

• git diff --check: passed.
• Not run: narrow local restore/build/test. The repo tooling hit Windows Schannel TLS failures while restoring packages from configured feeds in this environment. CI should be treated as the authoritative validation for the full test matrix.

[dotnet-policy-service]

Thanks for your PR, @imsouvik. Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[imsouvik]

@dotnet-policy-service agree